This type of roofing material conventionally used can include, for example, a structure as shown in Patent Document 1 as described below, or the like. That is, the conventional roofing material is a ceramics-based flat roofing material represented by a decorative slate for a house roof, and a cutout is formed at an end portion of the roofing material. When such a roofing material is arranged side by side on the roof base together with other roofing materials, the cutouts of the adjacent roofing materials are butted against each other, thereby aligning the roofing materials.
On the other hand, the present inventors have attempted implementing a metal roofing material as disclosed in Patent Document 2, i.e., a metal roofing material including a metal front substrate; a back substrate disposed on a back side of the front substrate; and a core material made of a foamed resin filled between the front substrate and the back substrate.